Display screen or portion thereof with transitional graphical user interface



FIG. 1 is a front view of the first image in a sequence for a displayscreen or portion thereof with transitional graphical user interfaceshowing our new design;

FIG. 2 is the second image thereof; and,

FIG. 3 is the third image thereof.

The outer perimeter shown as a pair of broken lines in the drawingsillustrates a display screen or portion thereof and forms no part of theclaimed design. The remaining broken lines in the drawings illustrateportions of the graphical user interface that form no part of theclaimed design.

The appearance of the transitional image sequentially transitionsbetween the images shown in FIGS. 1-3. The process or period in whichone image transitions to another image forms no part of the claimeddesign.

CLAIM The ornamental design for a display screen or portion thereof withtransitional graphical user interface, as shown and described.